Thrombomodulin in the sera of patients with multiple sclerosis and human lymphotropic virus type-1-associated myelopathy

Damage to the blood-brain barrier, which mainly consists of cerebral endothelial cells, has been demonstrated in multiple sclerosis (MS) clinically and histochemically. To investigate the endothelial cell damage, we evaluated the presence of soluble thrombomodulin in the sera of patients with MS and human T lymphotropic virus type-1-associated myelopathy (HAM) using an enzyme-linked immunosorbent assay. Serum thrombomodulin levels were significantly increased in patients with acute relapsing MS during an exacerbation and chronic progressive MS as compared with those of controls (P < 0.001, respectively). Patients with HAM also had higher serum levels of thrombomodulin than did controls (P < 0.001). There was significant difference between patients with HAM and seropositive non-HAM carriers (P < 0.01). These results suggest that the detection of serum thrombomodulin could be used as a marker of endothelial cell damage in inflammatory diseases such as MS and HAM.